3-Exomethylenecepham and 3-hydroxy-3-cephem sulfoxides represented by the formulas ##STR1## wherein R is an acyl group derived from a carboxylic acid and R.sub.1 is a carboxylic acid protecting group, are useful intermediates in the synthesis of 3-alkoxy-3-cephem, 3-chloro-3-cephem and 3-methyl-3-cephem antibiotic compounds.
3-Exomethylenecepham和3-羟基-3-头孢烷砜的
化学式分别为##STR1##其中R是来自
羧酸的酰基,R.sub.1是
羧酸保护基,它们是合成3-烷氧基-3-头孢烷、3-
氯-3-头孢烷和3-甲基-3-头孢烷抗生素化合物的有用中间体。